| Pos. | Spare part number | Name |
| A | - | Air intake from the air filter |
| B | - | Compressed air to the charge air cooler |
| C | - | Exhaust gas intake |
| D | - | Exhaust gas release |
| 1 | - | Oil supply line |
| 2 | - | Compressor housing |
| 3 | - | Rotary Electronic Actuator (REA) |
| 4 | - | Lever drive of the actuator for adjusting the position of the blades |
| 5 | - | Turbine housing |
| 6 | - | Turbocharger support bracket |
| 7 | - | Oil return line |
| 8 | - | Exhaust manifold |
The TD4 engine features a Garrett variable nozzle turbocharger with a rotating electronic actuator (REA). The turbocharger is mounted to the exhaust manifold on the right side of the engine and is secured to the cylinder block with a bracket. An oil line with a banjo connection is installed between the exhaust port on the right side of the cylinder block and the top of the turbocharger housing. It supplies pressurized oil to the turbocharger bearings. An oil line, secured to the bottom of the turbocharger, is connected to the oil pan and directs the return oil from the turbocharger to the oil pan. A heat shield is installed above the turbocharger and the exhaust manifold to protect other components and prevent accidental contact with hot exhaust system components.
The turbocharger includes a turbine and a compressor wheel mounted on a common shaft. They are enclosed in a cast housing. The common shaft is supported by two semi-floating bearings. The cast housing forms two chambers that tightly surround the compressor and turbine wheels. The turbine wheel is located in the exhaust gas flow from the engine and exhaust system. The compressor wheel is located in the intake air flow between the air filter and the outlet to the charge air cooler.
When the turbocharger is operating, the turbine and compressor shaft can reach a rotation speed of more than 200,000 rpm and provide a boost pressure of up to 1.7 bar. Inside the turbine chamber, a pressure of 3 bar in front of the turbine and a temperature of 800°C can be generated.
The REA elements are attached to the compressor housing and are connected by a lever mechanism to a rotating adjustment ring located in the turbine housing. A set of radial adjustable blades is located along the inner perimeter of the rotating adjustment ring. The adjustable blades are positioned so as to interrupt the flow of exhaust gases from the engine, in front of the turbine wheel.
The REA is controlled directly by the Engine Control Module (ECM). The ECM continuously controls the actuator position using input information from various sensors installed on the engine and vehicle. A feedback sensor in the REA continuously informs the ECM of the actuator position during turbocharger operation. When the variable vanes fail to achieve the requested position, a diagnostic trouble code (DTC) is stored in the ECM memory.
See the source on the website LRMAN.RU
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